/** Creates a function based on a user function */
public Function(UserFunction f) {
String[] names = f.getVarNames();
this.function = f;
this.argsNumber = names.length;
this.args = new Argument[argsNumber];
this.values = new double[argsNumber];
for (int i = 0; i < argsNumber; i++) {
String name = names[i];
args[i] = new Argument(name, f.getVarIndex(name));
}
}
/** Evaluates the function */
public double evaluate(DataRow data) throws Exception {
for (int i = 0; i < argsNumber; i++) {
Argument arg = args[i];
values[arg.index] = data.getVarDoubleValue(arg.varName);
}
return function.evaluate(values);
}
/**
* Adds a chart information to the existing chart panel
*
* @param node
*/
public void addSeries(Node node) {
// TODO: everything could be done with expressions only
String varNames = XmlDocUtils.getValue(node, "variable", null);
String label = XmlDocUtils.getValue(node, "label", "");
String expressions = XmlDocUtils.getValue(node, "expressions", null);
String exprLabels = XmlDocUtils.getValue(node, "expr-labels", "");
// Single variables
if (varNames != null) {
String[] names = varNames.split(";");
String[] labels = label.split(";");
int i = 0;
for (String name : names) {
if (name == null || name.length() == 0) continue;
label = labels[i];
name = name.trim();
addSeries(name, label);
if (i < labels.length - 1) i += 1;
}
}
// Expressions
if (expressions != null) {
String[] exprs = expressions.split(";");
String[] labels = exprLabels.split(";");
int i = 0;
for (String expr : exprs) {
if (expr == null || expr.length() == 0) continue;
label = labels[i];
UserFunction f;
try {
f = UserFunction.create(expr);
} catch (Exception ex) {
ex.printStackTrace();
continue;
}
addSeries(f, label);
if (i < labels.length - 1) i += 1;
}
}
}
@Override
public String toString() {
return function.toString();
}